Month: December 2012

During 1940 President Roosevelt had transferred the Pacific Fleet from bases on the West Coast of the United States to Pearl Harbor on the Hawaiian island of Oahu, hoping that its presence might act as a deterrent upon Japanese ambitions. Yet the move also made the fleet more vulnerable. Despite Oahu’s strategic importance, the air warning system on the island had not become fully operational by December 1941. The Signal Corps had provided SCR-270 and 271 radar sets earlier in the year, but the construction of fixed sites had been delayed, and radar protection was limited to six mobile stations operating on a part-time basis to test the equipment and train the crews. Though aware of the dangers of war, the Army and Navy commanders on Oahu, Lt. Gen. Walter C. Short and Admiral Husband E. Kimmel, did not anticipate that Pearl Harbor would be the target; a Japanese strike against American bases in the Philippines appeared more probable. In Hawaii, sabotage and subversive acts by Japanese inhabitants seemed to pose more immediate threats, and precautions were taken. The Japanese-American population of Hawaii proved, however, to be overwhelmingly loyal to the United States.

Because the Signal Corps’ plans to modernize its strategic communications during the previous decade had been stymied, the Army had only a limited ability to communicate with the garrison in Hawaii. In 1930 the Corps had moved WAR’s transmitter to Fort Myer, Virginia, and had constructed a building to house its new, high-frequency equipment. Four years later it added a new diamond antenna, which enabled faster transmission. But in 1939, when the Corps wished to further expand its facilities at Fort Myer to include a rhombic antenna for point-to-point communication with Seattle, it ran into difficulty. The post commander, Col. George S. Patton, Jr., objected to the Signal Corps’ plans. The new antenna would encroach upon the turf he used as a polo field and the radio towers would obstruct the view. Patton held his ground and prevented the Signal Corps from installing the new equipment. At the same time, the Navy was about to abandon its Arlington radio station located adjacent to Fort Myer and offered it to the Army. Patton, wishing instead to use the Navy’s buildings to house his enlisted personnel, opposed the station’s transfer. As a result of the controversy, the Navy withdrew its offer and the Signal Corps lost the opportunity to improve its facilities.

Though a seemingly minor bureaucratic battle, the situation had serious con­sequences two years later. Early in the afternoon of 6 December 1941, the Signal Intelligence Service began receiving a long dispatch in fourteen parts from Tokyo addressed to the Japanese embassy in Washington. The Japanese deliberately delayed sending the final portion of the message until the next day, in which they announced that the Japanese government would sever diplomatic relations with the United States effective at one o’clock that afternoon. At that hour, it would be early morning in Pearl Harbor.

Upon receiving the decoded message on the morning of 7 December, Chief of Staff Marshall recognized its importance. Although he could have called Short directly, Marshall did not do so because the scrambler telephone was not considered secure. Instead, he decided to send a written message through the War Department Message Center. Unfortunately, the center’s radio encountered heavy static and could not get through to Honolulu. Expanded facilities at Fort Myer could perhaps have eliminated this problem. The signal officer on duty, Lt. Col. Edward F French, therefore sent the message via commercial telegraph to San Francisco, where it was relayed by radio to the RCA office in Honolulu. That office had installed a teletype connection with Fort Shafter, but the teletypewriter was not yet functional. An RCA messenger was carrying the news to Fort Shafter by motorcycle when Japanese bombs began falling; a huge traffic jam developed because of the attack, and General Short did not receive the message until that afternoon.